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5‐Hydroxytryptamine 3 Receptors Sited on Cholinergic Axon Terminals of Human Cerebral Cortex Mediate Inhibition of Acetylcholine Release
Author(s) -
Maura Guido,
Andrioli Gian Carlo,
Cavazzani Paolo,
Raiteri Maurizio
Publication year - 1992
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1992.tb10983.x
Subject(s) - acetylcholine , agonist , ketanserin , cholinergic , chemistry , 5 ht receptor , cerebral cortex , receptor , endocrinology , spiperone , medicine , serotonin , biology , biochemistry
Synaptosomes prepared from freshly obtained human cerebral cortex and labeled with [ 3 H]choline have been used to investigate the modulation of [3H]acetylcholine ([ 3 H]ACh) release by 5‐hydroxytryptamine (5‐HT). The Ca 2+ ‐dependent release of [ 3 H]‐ACh occurring when synaptosomes were exposed in supervision to 15 m M KCl was inhibited by 5‐HT (0.01‐1 μM ) in a concentration‐dependent manner. The effect of 5‐HT was mimicked by 1‐phenylbiguanide, a 5‐HT 3 receptor agonist, but not by 8‐hydroxy‐2‐(di‐ n ‐propylamino)tetralin, a 5‐HT 1A receptor agonist. The 5‐HT 3 receptor antagonists tropisetron and ondansetron blocked the effect of 5‐HT, whereas spiperone and ketanserin were ineffective. It is suggested that cholinergic axon terminals in the human cerebral cortex possess 5‐HT receptors that mediate inhibition of ACh release and appear to belong to the 5‐HT 3 type.